Ever since he had his Marshall amps modified to go to 11 (as opposed to lame ol' 10), Spinal Tap lead guitarist Nigel Tufnel has had his finger on the pulse of the cutting edge of ... something.

For instance, how can we forget his famous amplifier capo?

"[Capos] were an obstruction to my hand as I was playing," a kilt-clad Tufnel (a.k.a. actor Christopher Guest) says in the brief amp-capo demo clip below. "So I thought, if I could put it 'round my amplifier speaker, I could move my hand up as much as I would like—and only have to learn how to play in one key."

"It's being manufactured as we speak, and it's about this big by this big (makes a few fisherman's gestures), and I strap it around the Marshall stacks which are about this wide (more fisherman gestures) and it goes around the bottom," Nufnel says. "What it does is, if you can only play in A it squeezes, sonically, the cones to shape the sound, pushing it up higher, lifting it. So you make a mark on the side of the speaker, say A, G, et cetera, and get the roadie to push it up.

"And I've got a new musical notation system as well, if we can talk about that… This is how it works… If you're reading a chord chard and it says A, B, C, etc., with my system it would say, One for A, Two for B… But you're a guitarist—see if you can figure this out… One, Two, One."

Um, anyway, for more this sort of thing, check out the complete 1992 interview here.

Because the amp capo video is so brief, we've thrown in a bonus clip of Tufnel discussing Steve Vai in 2011 (middle video).

"If I had a criticism of Steve Vai," Tufnel says, "[it 's that] he knows too much, frankly. And it's a bit annoying, you know. Oh yeah, play anything, play with your eyes closed, play in any key, perfect pitch, all that stuff." Enjoy!